House Bill 1490 began as just another incendiary hurled into Missouri’s volatile struggle over Common Core.

“Notwithstanding any other law, the state board of education shall not adopt, and the department of elementary and secondary education shall not implement, the Common Core State Standards…”

Now the bill stands as the vehicle carrying a startling compromise — an accord where none seemed possible — that is on the verge of becoming law.

It’s far from perfect. Partisans on both sides of Common Core’s multistate effort to establish high learning targets nationwide still see plenty of reasons to be nervous.

Under the bill:

• Missouri would join Indiana as the second state to drop out from the 45 states that had adopted the standards for math and English language arts.

• Working groups of Missouri educators would bear down over the next year and write new standards, which, after a public vetting and state school board approval, would go into effect in the fall of 2016.

• In the meantime, all the school districts in the state that have invested two to three years or more adopting Common Core would get to continue that work.

• The state also would carry forward a trial year using the assessments from the Smarter Balanced multistate consortium that are aligned to Common Core.

The educators working on the new Missouri standards could bring all of the Common Core experience into their working groups, with the expectation by many educators that most of those standards would re-emerge in the final product.

The much-changed bill has passed with strong majorities in both the House and the Senate. It is back in conference this week as a joint committee works out differences between the House and Senate versions.

The fact remains that groups that couldn’t hardly have been farther divided over Common Core are tolerating HB 1490’s middle ground.

Sen. David Pearce, the chair of the Senate Education Committee, gives it a good chance of becoming law.

The temperature had been rising over the past two legislative sessions, with superintendents, state administrators and teachers endorsing the work of Common Core before legislative committees — while other teachers and crowds of parents were shouting the standards down in the Capitol Rotunda.

Why is a compromise now possible?

One reason is that area superintendents and school boards who have invested so much in Common Core see a chance through the educator work groups to break away from so much public anger and confusion.

This relieves the greatest fear that lawmakers would “pull the rug out” from under schools, said Gayden Carruth, executive director of the Cooperating School Districts of Greater Kansas City.

“If this helps people understand about standards — that they’re not something evil — we can live with that,” she said.

Groups opposing the Common Core standards, particularly over what they saw as heavy-handed federal pressure to adopt them, like the chance for a fresh start.

“This puts the writing and crafting of Missouri standards back in the hands of Missouri educators and individuals,” said Gretchen Logue of the Missouri Coalition Against Common Core.

“It brings transparency to the process which we haven’t had,” Logue said.

Even with the compromise, there is still potential trouble down the road.

Common Core supporters are agreeable as long as the law preserves the work school districts have already done on the standards, and that the work of the groups writing the new Missouri standards resembles more of a fine-tuning.

Opponents of Common Core may not be happy if Missouri standards end up looking too much like Common Core.

Indiana’s new standards mostly reaffirmed Common Core, and “Common Core opponents are apoplectic,” said Mike Cohen, president of Achieve Inc., which was one of the major partners that developed Common Core.

“They were not placated at all,” he said.

He sees little reason for Missouri supporters of Common Core to have confidence under the bill that the state would end up with Common Core standards.

“And if you do,” Cohen said, “you’ll see another round of political fighting.”

Politics also could come into play in the selection of the working groups, several observers said.

The latest version of the bill from the Senate plans for two 16-member groups, one for grades kindergarten though five, and one for grades six through 12.

Different offices and groups would be responsible for picking one or more members, including the president pro tem of the Senate, the speaker of the House, the state school board, a state association of school boards, a coalition of administrators, the governor and the lieutenant governor.

The proposed work groups would each have four parents and 12 educators. The educators must have at least 10 years’ experience and have lived in Missouri at least three years.

If the bill passes, there surely will be much scrutiny of who gets appointed to the work groups, said Anne Gassel of the Missouri Coalition Against Common Core, but she expects the teachers will transcend the politics once they get to work.

“They know they will be taking this back into their classrooms,” Gassel said.

Missouri Education Commissioner Chris Nicastro, whose department has been strongly backing the work on Common Core, said in a written statement that the department would welcome the input of educators — which has been its regular practice in preparing and revising state standards.

“We have always relied heavily on district professionals to conduct this work,” the statement said.

State Rep. Kurt Bahr, a St. Charles Republican, filed the original HB 1490, and it has taken on amendments from several directions, including language from bills by Pearce and by Sen. Ed Emery, a Lamar Republican.

The bill still has to survive the last-hour bargaining that can happen as the session approaches its May 16 finale.

“We feel it’s moving in the right direction,” said Mike Lodewegen, the director of legislative advocacy for the Missouri Council of School Administrators.

“We can address some of the concerns of Common Core,” he said, “but protect the work educators have done and move toward more rigorous standards.”

That was not the sentiment when HB 1490 first landed.

“I’m surprised,” said Rep. Mike Lair, a Chillicothe Republican. “There is so much passion on both sides. I don’t think people realize the amount of work educators do to get ready to teach.”